cc: Adding creation location to debug BeginFrameArgs objects.

cc/output/begin_frame_args.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/output/begin_frame_args.h"
 
 #include "base/debug/trace_event_argument.h"
 #include "ui/gfx/frame_time.h"
 
 namespace cc {
 
+const char* BeginFrameArgs::TypeToString(BeginFrameArgsType type) {
+  switch (type) {

[picksi1, 2014/11/20 14:04:20]

should this be a const function?

[mithro-old, 2014/11/21 03:17:04]

Static functions can't be const.

+    case BeginFrameArgs::INVALID:
+      return "INVALID";
+    case BeginFrameArgs::NORMAL:
+      return "NORMAL";
+    case BeginFrameArgs::SYNCHRONOUS:
+      return "SYNCHRONOUS";
+    case BeginFrameArgs::MISSED:
+      return "MISSED";
+  }
+  NOTREACHED();
+  return "???";

[picksi1, 2014/11/20 14:04:20]

If this return value is Logged somewhere (in the trace events, I guess) it might
be helpful to explicitly say "UNKNOWN BEGIN FRAME TYPE" - it would also be
really nice to add the numeric value of the unknown type...

[danakj, 2014/11/20 16:03:02]

The NOTREACHED implies we never get to this line. We don't need to do anything
sane here.

[mithro-old, 2014/11/21 03:17:03]

This follows the approach in cc/scheduler/scheduler_state_machine.cc

This function needs to return a "const char*" so there is no way to include the
numeric value without leaking memory.

[mithro-old, 2014/11/21 03:17:04]

NOTREACHED() doesn't fail where DCHECK is not enabled, so we still need to
return something.

+}
+
 BeginFrameArgs::BeginFrameArgs()
     : frame_time(base::TimeTicks()),
       deadline(base::TimeTicks()),
       interval(base::TimeDelta::FromMicroseconds(-1)),
       type(BeginFrameArgs::INVALID) {
 }
 
 BeginFrameArgs::BeginFrameArgs(base::TimeTicks frame_time,
                                base::TimeTicks deadline,
                                base::TimeDelta interval,
                                BeginFrameArgs::BeginFrameArgsType type)
     : frame_time(frame_time),
       deadline(deadline),
       interval(interval),
       type(type) {
 }
 
-BeginFrameArgs BeginFrameArgs::CreateTyped(
-    base::TimeTicks frame_time,
-    base::TimeTicks deadline,
-    base::TimeDelta interval,
-    BeginFrameArgs::BeginFrameArgsType type) {
+BeginFrameArgs BeginFrameArgs::Create(BeginFrameArgs::CreationLocation location,
+                                      base::TimeTicks frame_time,
+                                      base::TimeTicks deadline,
+                                      base::TimeDelta interval,
+                                      BeginFrameArgs::BeginFrameArgsType type) {
   DCHECK_NE(type, BeginFrameArgs::INVALID);
+#ifdef NDEBUG
   return BeginFrameArgs(frame_time, deadline, interval, type);
-}
-
-BeginFrameArgs BeginFrameArgs::Create(base::TimeTicks frame_time,
-                                      base::TimeTicks deadline,
-                                      base::TimeDelta interval) {
-  return CreateTyped(frame_time, deadline, interval, BeginFrameArgs::NORMAL);
+#else
+  BeginFrameArgs args = BeginFrameArgs(frame_time, deadline, interval, type);
+  args.created_by = *location;
+  return args;
+#endif
 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat> BeginFrameArgs::AsValue()
     const {
   scoped_refptr<base::debug::TracedValue> state =
       new base::debug::TracedValue();
   AsValueInto(state.get());
   return state;
 }
 
 void BeginFrameArgs::AsValueInto(base::debug::TracedValue* state) const {
   state->SetString("type", "BeginFrameArgs");
-  switch (type) {
-    case BeginFrameArgs::INVALID:
-      state->SetString("subtype", "INVALID");
-      break;
-    case BeginFrameArgs::NORMAL:
-      state->SetString("subtype", "NORMAL");
-      break;
-    case BeginFrameArgs::SYNCHRONOUS:
-      state->SetString("subtype", "SYNCHRONOUS");
-      break;
-    case BeginFrameArgs::MISSED:
-      state->SetString("subtype", "MISSED");
-      break;
-  }
+  state->SetString("subtype", TypeToString(type));
   state->SetDouble("frame_time_us", frame_time.ToInternalValue());
   state->SetDouble("deadline_us", deadline.ToInternalValue());
   state->SetDouble("interval_us", interval.InMicroseconds());
-}
-
-BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor(
-    base::TimeTicks now) {
-  // For WebView/SynchronousCompositor, we always want to draw immediately,
-  // so we set the deadline to 0 and guess that the interval is 16 milliseconds.
-  if (now.is_null())
-    now = gfx::FrameTime::Now();
-  return CreateTyped(
-      now, base::TimeTicks(), DefaultInterval(), BeginFrameArgs::SYNCHRONOUS);
+#ifndef NDEBUG
+  std::string created_by_str("");
+  created_by.Write(true, true, &created_by_str);
+  state->SetString("created_by", created_by_str);
+#endif
 }
 
 // This is a hard-coded deadline adjustment that assumes 60Hz, to be used in
 // cases where a good estimated draw time is not known. Using 1/3 of the vsync
 // as the default adjustment gives the Browser the last 1/3 of a frame to
 // produce output, the Renderer Impl thread the middle 1/3 of a frame to produce
 // ouput, and the Renderer Main thread the first 1/3 of a frame to produce
 // output.
 base::TimeDelta BeginFrameArgs::DefaultEstimatedParentDrawTime() {
   return base::TimeDelta::FromMicroseconds(16666 / 3);
 }
 
 base::TimeDelta BeginFrameArgs::DefaultInterval() {
   return base::TimeDelta::FromMicroseconds(16666);
 }
 
 base::TimeDelta BeginFrameArgs::DefaultRetroactiveBeginFramePeriod() {
   return base::TimeDelta::FromMicroseconds(4444);
 }
 
 }  // namespace cc